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A lot of traffic between users and your site comes from the static content you’re using to set up the user interface, namely layout graphics, Stylesheets and Javascript files.

This article shows a method to improve the providing of static content for a web platform. Further, it will show you a way to automate the deployment of these files, so you can deliver them with least effort but with maximum performance.

This tutorial will take some time to set it up, but it’s going to save you hours of work in the future and will improve your page speed significantly.

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1. Why do I need this?

There are several approaches to optimize the delivery of contents.
Some use on-the-fly compression via the server itself or a scripting language, which costs performance and does not optimize the structure and content of the files.

The method shown here prepares the files once and also merges and optimizes the code of CSS and Javascript files before the files are compressed, which makes the delivery of them even faster.

Most browsers download only two files from a source at once. If a page needs to load more files from one domain, they get queued.

More files to transfer mean more requests to the server, more traffic and more usage of the server’s performance. For the users of the platform, this means longer loading times.

The more steps you need to deploy these files, the more space for mistakes is given.

Deployment is boring.. It’s far more exciting to invest some time once, to set up a reusable automation, than wasting time doing the same copy/paste/upload actions over and over again.

Compare this two screenshots that show the same content before and after the optimization.
The apricot colored parts of the bars stand for the status “in queue” while loading the page.

The “in queue” status means nothing less than: Wasted time of the user.

In this example, the loading time was reduced by 33%, the transferred data size was reduced by 65% and the number of requests to the server even by 80%.

By using CSS sprites and merged CSS and Javascript files, there is no queue for the loading of the basic static content.

2. How to improve your static content

Besides caching, there are some principles to make the whole setup of static content more efficient right from the start of development.

Use CSS sprites for your layout graphics. It not only saves you a lot of traffic and loading time. If you got used to maintain your graphics like this, you’ll notice that it can be much more comfortable to have your layout elements e.g. in a single Photoshop file.

Don’t blow up the loading time with your CSS and Javascript files. Combine the files of each kind into one single file, minimize them (e.g. by removing line breaks and other unnecessary characters) and compress them using GZip to get the load even smaller. This is covered in this tutorial.

3. Automating the deployment using Ruby

This automation is written in the Ruby language. So you need to have Ruby installed on your development computer. The installation is pretty simple on Windows and Mac OS X even ships with Ruby.

Please keep in mind: The scripts are completely independent from the language you’re using to run your site! You can also use them to deploy content e.g. for a PHP project.

If you’re not used to work on the command line, the next steps might look cryptic to you. Don’t hesitate, clench your teeth and take care that you always pass the correct path of the files to deal with. You only have to go through this once. When you’re finished, all you need to do is to type one single command to start the whole process.

To make it easier for you, this is the folder structure used for this tutorial:

Requirements for this tutorial

A command line tool, like Windows cmd.exe or Mac OS X Terminal to call the scripts.

A FTP account to try out the upload script.

A project to enhance.

Optional: The Firefox add-on Firebug (or something similar for other browsers), to see the enhancements afterwards.

Juicer

Christian Johansen created a tool called Juicer which enables you to merge and minimize CSS and Javascript files. To install it on Windows, simply type

gem install juicer

in the command line. When you’re using Mac OS X use

sudo gem install juicer

After the successful install, Juicer will ask you to extend it with YUI Compressor and JSLint for Javascript compression and verification. You do this by typing

juicer install yui_compressor

and after that

juicer install jslint

in the command line.

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Preparing your files

The good thing is, you don’t have to change anything in your present files. But to make sure, the files are merged in the order you want to, you need to set up two additional files.

The parameter -i means that the merging process won’t be cancelled, if JSLint thinks you have errors in your Javascript code. The parameter –force means older versions of the minified file will be overwritten.

For CSS:

juicer merge --force ./css/static.css

As a result you will see two new generated files named static.min.js and static.min.css. You probably want to know if they still work for your site, so go ahead and test it, by replacing the old bunch of link and script tags in your html header with the two new ones.

GZip Compression

When your minified files work fine, you can go on to compression. If you get Javascript errors or your CSS layout looks weird, you should re-check the order of the files to merge.

Below you see a small Ruby script that saves a gzipped copy of a file.

When you look at your folder, you’ll notice a new file called static.min.js.gz. Now do the same for the CSS file:

ruby gzip.rb ../css/static.min.css

Important: Make sure that your server provides the right content encoding and content type information to the clients, so they understand that this files are gzipped content.
You can do this in many ways. For Apache, an example for the .htaccess file would be:

Save it in a file called e.g. batch, insert your FTP credentials and call it like this:

cd deploy //switch to subdirectory
sh batch

And the content gets merged, minified, compressed and uploaded in one rush.
Additionally to the CSS and Javascript files, it would be a good idea, if the graphics file for the CSS sprites would be uploaded too? Just add an additional call of the upload script in the batch file. It can be used with any filetype.

4. In your template

Further development and bug fixing is hard to do in a minified file. But you can add an if-clause in your templates to vary the referencing of your files, depending on your environment.

Take the original files for your local development and the minified for your online version. Additionally you should check if the users browser supports gzipped content (most modern browsers do).

5. Get even faster with subdomains

Like mentioned before, most browsers only download two files per host simultaneously. You can bypass that rule by creating some subdomains for your static content and referencing the files through them.

For example, create a subdomain on your web hosting account, that’s called img.example.org, which points to example.org/img.

Do this for all of your folders, containing static content and use the subdomains to reference your resources:

This way, the rule won’t be applied and all files can be downloaded at the same time.

6. Conclusion

If you got all of this working for one of your projects, you surely recognized the advantages for you as a developer and for the users as the consumers of your content.

file_to_zip = ARGV[0]

puts “Gzipping #{file_to_zip}…”

base_name = File.basename(file_to_zip)

file_name_zip = “#{file_to_zip}.gz”

base_namezip = “zip#{base_name}”

File.open(file_name_zip, ‘w’) do |f|

gz = Zlib::GzipWriter.new(f)

IO.foreach(file_to_zip) {|x|
gz.write x
}

gz.close

end

puts “Gzipped version saved as #{file_name_zip}”

Save it as gzip.rb and call it like this:

ruby gzip.rb ../js/static.min.js

When you look at your folder, you’ll notice a new file called static.min.js.gz. Now do the same for the CSS file:

ruby gzip.rb ../css/static.min.css

Important: Make sure that your server provides the right content encoding and content type information to the clients, so they understand that this files are gzipped content.
You can do this in many ways. For Apache, an example for the .htaccess file would be:

Save it in a file called e.g. batch, insert your FTP credentials and call it like this:

cd deploy //switch to subdirectory
sh batch

And the content gets merged, minified, compressed and uploaded in one rush.
Additionally to the CSS and Javascript files, it would be a good idea, if the graphics file for the CSS sprites would be uploaded too? Just add an additional call of the upload script in the batch file. It can be used with any filetype.

4. In your template

Further development and bug fixing is hard to do in a minified file. But you can add an if-clause in your templates to vary the referencing of your files, depending on your environment.

Take the original files for your local development and the minified for your online version. Additionally you should check if the users browser supports gzipped content (most modern browsers do).

5. Get even faster with subdomains

Like mentioned before, most browsers only download two files per host simultaneously. You can bypass that rule by creating some subdomains for your static content and referencing the files through them.

For example, create a subdomain on your web hosting account, that’s called img.example.org, which points to example.org/img.

Do this for all of your folders, containing static content and use the subdomains to reference your resources:

This way, the rule won’t be applied and all files can be downloaded at the same time.

6. Conclusion

If you got all of this working for one of your projects, you surely recognized the advantages for you as a developer and for the users as the consumers of your content.

These examples don’t claim to be perfect. But if you didn’t approach to automate recurring tasks in your daily workflow as a developer, you hopefully have an idea now, how it could look like.

Always keep in mind, that computers were invented to spare you the boredom of repeating, simple tasks. So save your time for more important things.

Of course, this doesn’t have to be the end of the line. If you’re interested in the automatic deployment of whole applications, you should have a look at Capistrano. Again, it’s written in Ruby, but you can also use it for PHP platforms.